520 HYATT'S REVISIOISr OF THE 



no peculiarities are given by any one which could establish its identity. Esper's figure 

 may possibly enable some one to settle this question, but I have seen no specimen which 

 might be considered precisely identical. Dr. Ehler, in his recent review,^ appeal's to 

 have decided that Esper's original specimen belonged neither to the Sjmngia cavernosa of 

 Duch. et Mich., or to the Cacosponrjia cavernosa Schm., and my own observations have 

 led to the same conclusion. 



It was with the greatest difficulty, also, that I covild come to any conclusion with regard 

 to the form described by Duchaissing and Michelloti. It may be well to remark, also, that 

 the surface in this figure is even more wretchedly drawn than many of the others, and this 

 greatly increased the labor of obtaining a satisfactory identification. 



The principal characteristics of the form and surface ally this form so closely with sub- 

 species meandriniformis, that I can only separate it as a distinct variety. The forms of the 

 specimens (PI. xv, fig. 5) in our collection are more spreading than is usual in that variety, 

 and the texture is quite as soft, thovigh denser, perhaps, when the skeleton is dry. The 

 projecting cushions of fibre are similar in form to those of variety meandriniformis, but are 

 joined together in larger masses by a tissue of fine superficial threads, which also are often 

 less dense, and simply bridge the intermediate channels. This, and the tortuous and rather 

 shallow character of the channels, gives the surface a smoother aspect than is common in 

 the sls;eleton of meandriniformis. The oscules are very large,, and have a peculiar ragged 

 aspect in dried sj)ecimens. They look as if some one had made them by repeatedly run- 

 ning a knife into the animal while it was drying, and then omitted to clean out the interior 

 thoroughly, leaving sharp pinnacles of dried sponge cuttings projecting inwards, sometimes 

 so as to fill the centre, but oftener sticking out around the centre of the aperture, and more 

 or less completely joined to the wall of the canal. This chai'actcristic ragged look is some- 

 times also to be seen in the oscules of sub-species gossypina, but never so decidedly. The 

 typical form is also known commercially as " Velvet Sponge." 



Loc, Key West, Nassau, in Soc. Coll. 



Sub-species cerebriformis. 



Spongia cerebriformis Duch. et Mich., Op. cit., p. 32, pi. 3. 



Variety typica. The aspect of this species, commonly known as one of the " Grass 

 Sponges " is very similar to that of Spongia agaricina, sub-species corlosia, var. typica. 

 The difference consists principally in the aspect of the surface. This is broken up by j^ar- 

 allel longitudinal ridges of irregular length on the sides, each ornamented with one or two 

 lines of tufts. These ridges extend on to the upper surface, giving them a markedly 

 radiatory arrangement. The larger orifices are situated in rows in the channels between 

 the ridges. The specimen figured (PI. xv, fig. 7) is probably in every way identical with 

 that figured in Duchaissing and Michellotti's work. 



Variety joZcma. This variety (PL xv, fig. 8) seems at first to l)e identical with complan- 

 ata and circuJaris of Duch. et Mich., but the figure given of Spongia circrdaris and the 

 descriptions of both species, are not favorable to such an identification. The general form 

 of the typical variety is very much compressed, being hardly ever more than three inches in 

 depth, without much reference to the breadth ; some specimens of this depth being eight 

 or nine inches in diameter, while others are only two or three. Large specimens are very 



* Die Espersclien Spongicn. p. 6. 



